The present invention generally relates to cases for disc-shaped recording mediums, and more particularly to a case for a disc-shaped recording medium comprising a jacket for accommodating a disc-shaped recording medium and a closing member for closing an opening of the jacket, and in which the closing member has a construction capable of distinguishing types of the disc-shaped recording medium, and reproducing side of the medium, and the like, in cooperation with detection switches disposed asymmetrically on the left and right sides with respect to a center of a reproducing apparatus.
Generally, a disc-shaped recording medium (hereinafter referred to as "disc") which is recorded with information signals such as a video signal and an audio signal with high density, is accommodated within a disc case in order to protect the surface of the disc from dirt, scratches, and the like. Conventionally, there was a disc case comprising a rigid jacket for accommodating a disc, and a tray having a front part which is engaged by engaging means upon complete insertion of the disc case within a reproducing apparatus and an annular or ring portion fixed to the front part for encircling the outer periphery of the disc. The above reproducing apparatus which operates together with the disc case accommodating the disc, is constructed so that when this disc case is inserted within the reproducing apparatus to a predetermined position, the engaging means of the reproducing apparatus engages to and holds onto the front part of the tray. Hence, when the jacket is pulled out from within the reproducing apparatus, the disc is held by the annular portion of the tray and relatively slipped out from the jacket at the above predetermined position, and the outer peripheral edge part of the disc rests on and is supported by a supporting mechanism within the reproducing apparatus. Then, a turntable relatively rises within the inner side of the supporting mechanism, and the disc is placed onto and is unitarily rotated with the turntable, to perform the reproduction. After completion of the reproduction, when the empty jacket is inserted into the reproducing apparatus, the disc is relatively inserted into the jacket together with the annular portion of the tray, and the engagement of the engaging means is released. Accordingly, when the jacket is pulled out from the reproducing apparatus, the disc and the tray is obtained outside the reproducing apparatus together with the jacket in a state in which the disc and the tray is incased inside the jacket.
In the above reproducing apparatus, when the disc is placed on the turntable, the disc is not visible from the outside. Accordingly, it is not possible to recognize by naked eyes from the outside whether the disc is being loaded or not, whether a disc side to be reproduced is a first side or a second side of the disc, whether the recorded signal is a television signal or a PCM audio signal, whether the audio signal is stereo or monaural.
Accordingly, in U.S. patent application Ser. No. 229,303, now U.S. Pat. No. 4,360,845, entitled "CASE FOR A DISC-SHAPED RECORDING MEDIUM" in which the assignee is the same as that of the present application, a case for a disc-shaped recording medium was proposed in which a closing member for closing an opening of a jacket has a shape having cutouts formed at specific positions in accordance with peculiarity of a disc accommodated inside the jacket. When the disc is loaded into the reproducing apparatus, microswitches confronting the cutouts of the closing member remain OFF and microswitches confronting non-cutout part of the closing member are pushed and are turned ON. According to output from the microswitches, there can be obtained signals such as disc side detection signal.
In this case, the closing member is required to be formed with a pair of cutout and non-cutout, disposed at left and right sides along the front side, for each item to be discriminated, which item includes item for discriminating whether the disc is being loaded or not. In connection with it, for the reproducing apparatus, a pair of microswitches is needed for every item to be distinguished.
Thus, when the items to be distinguished become large, a large number of pairs of cutout and non-cutout regions must be formed in the closing member.
On the other hand, since the closing member has cutouts of large-size to be engaged with locking means, formed at the front edge thereof, a space for forming the cutout and non-cutout for discrimination is rather narrow. Additionally, when disposing the microswitches sideways in a line, intervals provided between adjacent microswitches cannot be set so small. Therefore, the number of pair of cutout and non-cutout actually formed on the closing member is limited to a rather small value, and the number of items of discrimination is insufficient, thereby being not able to cope with the actual requirement.
Furthermore, as for the reproducing apparatus, since it requires a pair of microswitches for each discrimination item, a large number of microswitches are required; therefore a circuit becomes complex and the reproducing apparatus becomes expensive.
Still furthermore, since intervals between the adjacent cutout and non-cutout, and between the actuating pins of the adjacent microswitches become narrow inevitably, even there easily occurs error in discrimination operation caused by a probable very small error in position of the lid plate locked in the reproducing apparatus.